Weak lensing for precision cosmology

TL;DR

Weak lensing is a powerful tool for understanding cosmic structure and dark energy, but systematic uncertainties must be carefully managed and improved for reliable future cosmological insights.

Contribution

This paper reviews current systematic uncertainties in weak lensing measurements and discusses methods for their detection and mitigation to enhance cosmological precision.

Findings

Identification of key sources of systematic errors

Discussion of automated systematics detection methods

Emphasis on improving measurement reliability for dark energy studies

Abstract

Weak gravitational lensing, the deflection of light by mass, is one of the best tools to constrain the growth of cosmic structure with time and reveal the nature of dark energy. I discuss the sources of systematic uncertainty in weak lensing measurements and their theoretical interpretation, including our current understanding and other options for future improvement. These include long-standing concerns such as the estimation of coherent shears from galaxy images or redshift distributions of galaxies selected based on photometric redshifts, along with systematic uncertainties that have received less attention to date because they are subdominant contributors to the error budget in current surveys. I also discuss methods for automated systematics detection using survey data of the 2020s. The goal of this review is to describe the current state of the field and what must be done so that if weak lensing measurements lead toward surprising conclusions about key questions such as the nature of dark energy, those conclusions will be credible.